Steam plant



BEST AVAILABLE COP:

May 25 1926.

J. RUTHS STEAM PLANT Filed April 29, 1925 2 Sheets-Sheet l 3144mm a W BEST AVAILABLE COP J. RUTHS May 25 1926.

STEAM PLANT 2 Sheets-Sheet 2 Filed April 29, 1925 Figllz grvve'ntoc BEST AVAILABLE COP Patented May 25, 1926.

Urnrso STATES PATENT QFFHZE.

JOHANNES RUTHS, OF DJURSHOLM, SWEDEN, ASSIGNOR 'IOj AKTIEBOLAGET VAPOR- ACKUMUZLATOR, OF STOCKHOLM, SVFEDEN, A CORIORA'I'ION OF SWEDEN.

Application filed April 29, 1925.

the surplus of steam generated over that consumed by means of cold water; regulating the amount or condensing water so that-the condensed water is at a constant desired temperature; storing the hot water ,thus prepared and withdrawing the same as fdesiredfor use as feed water for boilers or for hot water .usein industrial processes, etc; My invention further involves the ap paratus for carrying this method into effect. "Amongstthe purposes of my present invention are; to equalize between heat generation and heat consumption in a steam plant particularly where variations are such that equalization can be efiected through feed .water reserve or where there is a demand for hot water forindustrial purposes; to increaseproduction in a steam plant; to increase etficiency of a steam plant; to take care of variable supply of heat to a boiler; and to maintain constant pressures in all Y the various parts of a plant.

By the present invention an accumulator can be built which issmaller and less costly than the known steam accumulator of variable pressure; boiler firing can be made entirely independent of consumption of steam or hot water; hot water is aways in reserve in any desired quantity, and of given constant temperature; boilers can be run with the best etliciency and other advantages are obtained as will be apparent from the description following.

My invention also involves certain features such as method and means for regulating. boiler fires in a plantas herein set out and. a safety arrangement for high water level in the accumulator.

:Other purposes and features of the inven tion will be apparent as the description procoeds which is to betaken in connection with the accompanying, drawings wherein STEAM PLANT.

Serial No. 26,727.

Figure I shows a plant according to the present invention and including the essential features necessary to carrying out the operation as herein set forth.

Figure II shows details of one form of overflow valve used in the plant of Figure 1.

Figure HI shows a detail of an indicating device used in the plant of Figure I.

Figure IV shows a simplified form of plant embodying my invention wherein hotwater is prepared solely for use in boilers.

Figure V shows diagrammatically a simplitied form of plant wherein hot water is prepared solely for industrial use.

Figure VI shows a plant wherein a motor is inserted between boilers and accumulator to extractpower from the steam pressure drop between the two.

Fig. VII shows a modified arrangement of hot vater preparing apparatus.

My invention is applicable to steam plants having any kind of: boilers or producing steam in any manner. For purposes of illustration I have shown in the steam plant of Figure I a steam generator comprising two boilers; a boiler 10, the firing of which is adapted to be regulated by a fire room force, the particular boiler shown being fired with coal; and a second boiler 9 the heat supply to which is not adaptedto be regulated to any great degree, the boiler shown consisting of a waste heat boiler supplied with hot gases leavin open-hearth furnace S and supplied to the boiler through waste heat also the supp y pressure for the-.1 consumer 12. The valve 15 operates to maintain a constant pressure in conduits 11 and'13, and allows the surplus of steam generated over what is used by consumer 12 'top'a'ss into accumulator A. where it' is condensed by cold water and in which hot water formed from the mixture of steam and cold Water is stored.

A designates my novel heat accumulator which might be termed a constant temperature, variable Water level accumulator since it is a characteristic feature of this accumulator that in normal operation its temperature is maintained constant andthe' amount of the same: that is, the accumula-.

tor should Ice-designed so that it can always receive and store the difference between what is generated by boilers and what is consumed by consumers connected in 'front of theoverfiow valve, regardless of how large this difference may be.' This matter" depends however on the'manner in which itis desired that the boilers he; fired. By greatervariatmn of fire intensity smaller accumulators can be used,- However, having in mind independence of boiler firingan d"flea-m'-"and=heat consumption the accu mulator will'be' designed most rationally it' it isjof sufficient capacity so'that none -or VQJILY slow c-hange's of 'fire intensity under the boilers ne'ecl' -take plac'epor, where the heat-to the boilers is supplied by Waste gases, so that no'gases needbe thrown awayor so that manually controlled boilers'working in connection with waste' heatboilers need not be fired too unevenly. I

Steam enters the accun'mlator tl-irough the steam charging device I6 which," in the illustration shown, comprises a circular steam loop to Whichis-attachcd a series of nozzles 17. This charging device lies in the water space 21 ot'the accumulate-r.

Cold water is supplied to the accumulator through thecold water supply pipe 20, and issprayed into the steam space of the accumulator through the cold Water spray device 19 The-amountot cold Water supplied through pipe 20 is regulated so that a constant temperature is maintained in thc accumulator Aw This is accomplished by means of a. coldrwater regulating valve- 2-3, which is controlled by-anfactuating mechanism-24 comprising'a' diaphragm 25 which diaphragm is" influenced -on the one side by a spring :26, and on the othersijde by-the pressure-of a. volatile liquid in chamber 28. Tube 29. connects chamber 28 with ajtherm'ostat-'iifiOsvhich isisituatedin the accumulator,

fpresent invention and trcularplant.

BEST AVAILABLE COP preferably in the water space thereof. The thermostat may be of any known kind comprising a casing enclosing volatile liquid.

As steam enters the accumulator through conduit ll and charging device 16 the temperature increases a very small amount. 'I he volatile liquid in thermostat 39 then expands and the increase of pressure due to expansion is transmitted to diaphragm 25 whicn moves the discs of valve 23 u wardly, thus opening more or less the valve 23, allowing cold water in increased amount to enter the steam space 22 through spray device 19 thus condensing steam and lowering the temperature by the small increment of increase so that the temperature is returned to its normal value. The arrangement thus maintains a practically constant temperature in the accumulator.

Hot water may be ex racted from the accum later for various purposes. For industrial purposes I have shown hot Water consumers 31 connected to receive hot water from the accumulator by means or hot water conduit 32. The hot water consumers 31 may, as is obvious, be of any kind, for example dye vats, washing machines and the like. Ihave shown a heat exchanger 86 of the indirect type inserted between the accumulator and consumers 31- since' with the arrangement of Fig. I, I plan to have the temperature in the accumulator higher than that used by consumers 3l'and the exchange thus takes out heat from the hot water before its pressure is lowered. The arrangement of consumers is immaterial to the depends upon the par- For boiler feeding hot water is extracted through the feed conduit 33 by means of a great deal under boiler temperature, there by allowing theheat of oil-take gases to be recovered in air preheaters which gives higher etficiencv than economizers. By combining this advantage with that of independence of heat generation and heatconsumption my invention provides a highly eflicient plant.

. In Fi'g. I, 87 designates an air pr'el-ieater for the boiler-lOfwhic-h may best any desirednkindgsupplying hot air to the turnaceot thebeilenthrough conduit- -88.

Figure II shows details of construction of one form of overflow valve adapted to be used with a plant laid out in accordance with the present invention. The valve comprises a casing enclosing a set of discs forming what is known as a balanced valve. The valve discs are attached to a spindle 21 which is connected to an operating mechanism lZ which operating mechanism comprises a diaphragm l3 firmly connected to ahousing-l l which is secured to the main'valve casting by means of legs all). Diaphragm 42-3 is attached at its center to the end of spindle all, and rests against a backing plate 46 also attached to the spindle. The diaphragm 43 forms one side of a chamber 47 to which an operating fluid is conducted through a restricted pipe 48. This operating fluid may be of any kind whether gaseous such as air, or liquid such as Water or oil.

The operating fluid leaves chamber 47 through an orifice 49 controlled by a checking member 50 attached to a second diaphragm 51, which is influenced, on the one .side, by the pressure in conduit 14 infront of the valve 15, the pressure actingthrough tube 52, and on the other side'by the combined influence of the actuating fluid leaving the orifice 49; and a spring f53. Theopcrating 'fluid .lea-vesvthe housing and is allowed to'fiow into the airor otherexhaust means through port 5%. A spring extends betweenbacking plate- 46i and-fixed abutment 56.

- The operation of the valve is as follows: .1

Suppose the valve-15is in the position indicated on-the drawing. Now suppose that the pressure in "conduit 14; ahead of the valve rises somewhat. The increase of pressure is transmitted through tube-'52 onto diaphragm- 51, which is moved against the action of spring 53 to throttle the orifice opening '49. This causes an increase-of pressure in chamber 47 whereby diaphragm 43 is moved against the action of spring 55 so that the valve discs 40 are caused to move to open the valve more and allow more steam to pass through. which allowsthe pressure in conduit 14 ahead of the valve to fall, whereby returning it to the desired constant pressure.

Suppose, on theother hand, that the pressure falls in conduit 1a ahead of the valve. The diaphragm 51 then causes member 50 to move awayfrom orifice opening 49 due to the preponderance of force of spring 53 added to the pressure of fluid leaving the orifice opening. over the pressure exerted through tube 52, whereby, due to the restriction in pipe 48, shown in Figure I as a hand valve 57, the pressure decreases in the chamber l? and spring 55 overcomes the opposing ell'eot of fluid pressure in chamber 47, and; valve discs-4O aremoved to close lator to bejcondensed.

BEST AVAILABLE COP ,8

the main valve whereby the pressure in conduit 14 before the valve is returned to normal. By this means a constant or substantially constant pressure can be maintained in conduits 11, 13 and in the boilers.

When the consumer 12 is such that steam used by the same can be condensed and is in proper condition to be used as jeed water or for certain industrial purposes, the same may be led into the accumulator A to be fed to the boilers or used-as hot water. The means which I show for doing this include motor driven pump 7-3 which draws condensate from condenser 77 and leads the same into container 78. In the container 78 is a float 79 which operates when the level in container 78 falls below a predetermined value to open valve 80 in cold water conduit 20. \Vater is drawn by pump 83 through pipe 81 and check valve 82 into conduit 20, and is supplied to the accumulator A. By this means the pump 83 dways takes the water from container-78 first and only see ondarily from the outside cold water supply. For this operation, as is obvious, the" supply pressure from the outside source must'oe greater than the height of water in the container 79..' This-arrangement permits the storing of the water in theZ-cori- -:ta1ner:78-*at times when there 1S-S0 much steam used by consumer 12 that very -little passes through overflow valvelz'i. jIt isobvious that at such timesthegreatestz quanlator. Condensed A water is therefore stored up in container 78., and led to the accumulator later .when there 1S-l6SS demand for steam so that more passes-into the accumu- The present invention presents an advantage over plants-containing an accumulator of variable pressure that special esigns o'l' turbines to take steam from accumulators can be avoided. 1 I 1 Further there is no restraint, onthe amount of steam generated. lVith some. systems now in use steam is usedto'heat feed I water but there is always a restraint ut on the boilers.v A- close regulation of tires-is necessary. Such systems regulate the amount of steam supplied 'to heat cold water and when 'the momentary afnounflofhot feed water is obtained at-fthe proper temperature, the steam supply is shutoil and boilerz-fires must be reduced in-intensity-in corresponding degree. My system-however uts no such limitation onthe boilers.

team may be generated .in any desired amount jatsall times and the .difierence be t-\veen' generation andconsumption will alcways lac-accumulated;- .a; --,i

Furthermore, by means ot-the overflow valve the advantage of constant pressure in the boilers is obtained. It is always con sidered evidence of good working in a boiler house when the boiler pressure diagrams approximate as closely as possible to straight lines. This gives constant pressure for auxiliaries and for main engines, high efiiciency of boilers, evenness of control of water level in boilers and other recognized good operating points.

Vith constant boiler pressure, no accumulation reserve remains in the steam boilers but this is well taken care of by the accumulator.

As stated the manner of firing the boilers depends somewhat on the type of plant. While the accumulator could be designed of suihcient size to take care of all variations with even firing of boilers, it will probably be found most suitable in the majority of cases to vary the boiler firing along slow gradually changing curves.

With the overflow valve as herein used the boiler pressure never varies, the gage 89 always showing a constant value regardless of conditions of steam reserve in the plants so that the fires cannot be regulated as in an ordinary steam plant but some other means must be used to vary the boiler firing.

To take care of this matter I propose to control the fires in a manner somewhat similar to the method of controlling the fires in a plant equipped with a steam accumulator of varying pressure as set forth in my c-opending application Serial No. 305,622, Patent No. 1,585,790.

That method comprises regulating the fires in accordance with extreme values 01" steam pressure in the accumulator. While in the variable pressure steam accumulator of the above mentioned application the steam pressure is a function of a state of charge, in the constant temperatm'e, variable water level accumulator of this application, the height of water in the accumulator is a function of the state of charge, wherefore I propose herein to use the height of water level in the accumulator as a factor for regulating the fires.

To this end Figure I shows means for indicating in the vicinity of the coal fired boiler 10, the height of water level in the accumulator A. This means comprises a vertically posited tube 58 of any suitable eX-pansible metal which is connected to the steam space 22 and the water space 21 of the accumulator A, by means of tubes 59 and 60 respectively. The lower end of tube 58 is firmly fixed as by means of bracket 61 firmly secured to the accumulatorshell. The upper end moves in response to changes of temperature due to changes of water level'in the accumulator A, and-consequently in the 1,585,791 BEST AVAlLABLE COP tube 58. The upper end otthe tube 58 being movable, tube 59 is supplied with a loop to take care of expansion. Movement of the upper end of tube 58 is transmitted by means of lever 62 pivoted at point 63 to a rod 6%: which is connected to an expansible member 65 shown in Figure III. The expansible member 65 which may be an inverted flexible metal bellows is so mounted that its move ment will change the volume in chamber 66 between the bellows 65 and cylinder 67. In the chamber 66 and pipe 68 is a non-compressible liquid which acts as an agency for transmitting movement of the free end of bellows 65 to a suitable indicating means on the dial gage 69 placed in the vicinity of the boiler 10.

The mode of operation of this apparatus will be readily understood to those skilled in the art without extensive explanation. If the water level in accumulator A recedes, rod 58 expands and rod 6a is moved downwardly whereby liquid passes from pipe 68 into chamber 66, and the dial on gage 69 is moved to indicate the corresponding movement of liquid in pipe 68. The dial on gage '69 can thus be moved to indicate the actual water level in the accumulater A. This dial is preferably graduated to show a range of water levels where the intensity of the fires are unchanged, for example between, water levels 0 and (Z.

hen gage 69 shows the water level higher.

than (1 the fires in boiler 10 are slowly checked until the water level again recedes. If the water level falls below value c the intensity of the fires is slowly increased, so that more steam is supplied to the accumulator A, and the water level returns to the normal range. In the meanwhile in the plant shown in Figure I the firing of boiler 9 is allowed to proceed as gas is received from the waste heat supply conduit 70.

In case the water should for some reason rise to too high a level in the accumulator, it may be well to shut oil the supply of steam thereto. This will increase the pressure in the high pressure line and therefore the boiler pressure, possibly blowing the safety valves. This is a condition that should not be enpected co-happen, but may be well as a sort of safety measure to apprise the attendants in the fire room when the water is unduly high in the accumulator. For this purpose I show in Figure I, a valve '71 which controls a conduit '72 branched into conduit s8. Pressure of the operating fluid in the conduit 72 together with the action of spring 73 keep valve Tl normally closed. The valve stem of the valve 71 projects into the accumulator and is adapted to be contacted by a lever Tl, whicn is connected to a float 7 so that when the float is liftedbyqthe; water to' a" predetermew-. BEST AVAILABLE COP.

mined aliqtridlevel, the lever "7e moves the valve :stem outwardly -:wlier-ehythe valve is open :an'dtheprcssureot the fiuid acting in 'chamheufi of the :valve housing t l connected withthe overflow :fifllVB 15 is released, :whereby spring ooz-moir'es-the overflow waive to:closing position, th-usshutting elf the steainusupply'tothe accumulator.

In the: plant shown .diagrzunmaticzilly in 10 F igure'IV, I use-:my-hot water accumulator 'A-simply to feedavater to the boilers. Such aplantnis !-possible where :the variations in i steam' consumption: are; not'L reat and yet a complcteiequalization can-be obtained in the plant.

F-i'gure V ishotrs anearrangement where .a -w'asteiheat boileii9 supplied withugases from an industrial 'fu-rnacei ior. example a rotary kilir-fiilisupplies: stea1nto the 'illOli i water ac- -cu-mulatoi" from which- -.water is extracted only for industrial purposes. a-In, this case -the're is no.:steam;consunier'connected ahead ofithe'ioverfiow valve;:andthe overflow valve in 1tl1is:-'case servesmerelytto;keep aiconstant pressure :in the i-hoilerszzwhile rallo\\ 'ing; passa'ge-'E- tl1rougli the asame ofathe i'v-ariable amount -:of isteam generated. .Theoverflow valve in this caseiallowsz. a: lower 'pressure inthe accumulator-than .in the boilers, and 3"yetunaintains a-.-constantboiler pressure regardless off-variation in L steam productions.

In the plant diagrammatically illustrated *in Figure VI a-mobdrsuclr-as a turbine 85is inserted':betweenr the boiler 10.- and the .hot

i '35 water accumulator-A. -*:This isadaptable for --cases where it: is 2 desired to 'run 1 the: accumulator at an appreciably .lowe1's.pressure 1 than that-ot-t-heboilers,-i1rwl1iclrcase the turbine 85 extracts-power:itrom the pressure '40 drop between the-boiler and the hotwater accumulator.

-'--As shown in Figure-VII the iuixing-ot' -stea1n andcold water to form hot water neednottake=place-in the accumulator itselfi-hut may take placedn a separate receptacle, and thenled-t0 the accumulator.

' and stored. In the arrangement-sh .rn in Figure VII, steam is supplied to=the receptacle 95 'throughconduit-'14 and water through conduit QO-controlled by valve 23 in response to temperature :as in Figure I.

Steam passes into nozzle ;91 carrying water with it, and is condensed thereby. The hot Us water= thus prepared then passes through of the accumulator apparatus. The thermostat inthis case is placed in a-pocket 94 arranged in theconduit 92.1111 such a case I the water level in the accumulator reservoir 93 will=i7ary: in thea-same manner as in the accumulator of Fig. I.

' Thisseparate pieparation'of:the-hot water may-also be accomplished by using arecep- V tan-1e built .in =.-mannersimilar to the accu- ""Hl1ll1t0ll A1 butrof much smaller: size' which =conduit 92 and-into the-storage reservoir 3- serves, like the receptacle95to preparethe hot water which is then conductedfto a larger receptacle in which it is stored.

As is obvious to those skilled in theart various changes in construction and operation are possible within the scope of the invention.

Althoughal-ways. preferable, in some cases the overflow valve ma be omitted or other mechanisms may be su stituted for the same.

flhepresent, application is to heconsidered as relating back for all common suhjectmatter to the-filing date of my copending application .Ser. No. 611 ,535.fi1ed January'8th, 1 923, andtothe rights incident thereto.

As pointed; out in that 7 application, steam may a so be-extractedirom theaccumulator. In the embodiment shownin FigYI, this may hedone thronghconduit gl'f. opere mi euSe a einPprai-"rr0p e .perature in-the accumulator." lfllhishetion I consider, as; within the scope of ,myifnyen- .tion vand not in variance with thehasieidea of constant temperature accumulation. .Accum ulationanay be effected in combined. constant temperature mid, variable .pressiire manner.- v 7 Y Having particularly .described and ascertained the mtu re gfi any. ,invention and the manner-in .which the s a1ne is. ;to he. per- -.t'ormed,.what I claim and desire to .pijo ct by; V tters Patent. of the United. States -is 1.- In asteain plant including asteam genorator, ,in A combination, an .accun1ulato1',

. means to; s upply- .surplusssteam geu rated over-momentary.steam demand t sa-id accumulator, means to I supply -.c0ld water to "said accumulator proportion to the steam supplied to obtain-hot watenpf given tempcrature, means t withdraw hot water from said accumulator .at a rate corresponding to the rate of demand for ,hot water, the; difference between the .hot water demand and .the hot water produced being retained in the accumulator.

2. In a steanr-plant, in combination, a steam. generator, a steam consumer, a constant temperature, .variahle water level accu1m1lator- .-means .to conduct steam from saia generator to SaidStGililLCOHSIUDBP, means to conduct; the surpl-usro't steam not COllStlil'lQil above that generated to said accumulator. I'HQZUISIO supply cold water to saidacruamlater, automatic means to regulate the amountof coldwater supplied to maintain a constant temperaturein said accumulator and-means to withdraw hot water from said accumulator.

3. In a steam. plant, in -coinbi nation, a steam generator, a constant temperature. Ya

-- riahle water. level accumulator, a passage for steam from said-generator to said accumulator, ,valve mechanism in said-p ssage. operatingto maintain a constant pressure. in s the steam-generator, means to supply cold Water to said accumulator, automatic means to control the cold water supply in response to temperature in the accumulator and means to conduct hot water from said accumulator to said steam generator.

4. In a steam plant, in combination, a steam boiler, a variable supply of Waste heat for said steai'n boiler, a constant temperature, variablefivater level accumulator, a passage for steam from said boiler to said accumulator, valve mechanism in said passage operating to maintain a constant pressure in the/boiler, means to supply cold water to said accumulator and operating to maintain a constant temperature in the accumulator, hot Water consumers and means to conducthot water from said accumulator to said hot water consumers.

5. In a steam plant, in combination, a steam generator, a constant temperature, variable water level accumulator, a passage for steam from said generator to said accumulator, valve mechanism insaid passage operating to maintain a constant pressure in the steam generator, means to supply cold water to said accumulator, automatic means to control the cold water supply and operating to maintain a constant temperature in said accumulator, an indicator mounted in the vicinity of said steam generator and mechanism responsive to changes of water level. in said accumulator and in dicating said changes upon said indicator.

6. Ina steam plant, in combination, a steam generator, a steam consumer, a constant-temperature, variable water level accumulator, "means to conduct steam from said generator to saidsteam consumer. means to conduct thesurplus of steam not consumed above that generated to said accumulator, means to control the last mentioned means and operating to maintain a constant pressure in the generator, means to su l cold Water to said accumulator, automatic means to regulate the amount of cold Water suppllcd to maintain a constant temperature in said accumulator, means to extract and use hot water from said accumulator, means to condense steam passing through said steam consumer, and means to conduct condensate thus produced to said accumulator.

7. In a steam-plant, in combination, a steam generator, a constant temperature, variable Water level accumulator, assagefor steam from said generator to said accumulator, a valve controlling said passage, and

means operated by a predetermined high level of Water in said accumulator to close said valve.

8. In asteam plant, in combination, a steam generator, a steam consumer, a constant temperature, variable water level accumulator, means to conduct steam from saidgenerator to said steam consumer,

means to conduct steam from said generator to said accumulator, means to condense steam used in said steam consumer, a container, means to conduct the condensate to said container, means to supply cold water to said accumulator from an outside source, means to supply Water from said container to said accumulat r, and means responsive to height of liquid in said container to cut oil the supply from the outside source.

9. The method of generating and dispensing energy in a steam plant which comprises generating steam at constant pressure and normally in excess of steam demand, condensing the surplus steam by means of cold Water, regulating the supply of cold Water so that the hot water produced by the mixing of steam and cold Water is maintained at constant temperature, accumulating hot water thus produced and using the hot water as desired.

10. In a steam plant including a steam generator, in combination, a constant temperature, variable water level accumulator containing Water at different heights for dillerent'. times, means to supply surplus steam generated over momentary steam, c emand to said accumulator, means to supply cold water to said accumulator to condense said steam and produce hot Water,'saidac-' cumulator being constructed and arranged to store the hot water produced until there is a demand "for the hot Water, and means responsive to the temperature in the accumulator to control the supply of cold Water and ferent times, said accumulator comprising a receptacle closed to the atmosphere and adapted to operate at different pressures than atn'iospheric pressure and containing a steam space and a water space, a steam charging device in the Water space of. the accumulator, means to supply surplus steam generated over momentary steam demand to saidsteam charging device,'means to supply cold Water to said accumulator to condense said steam ahd produce hot Water, said accumulator being constructed and arranged to store the hotwater produced until there is a demand for the hot water and means responsive to the temperature in the accumulator to control the supply of cold Water and O] )Qlz1i'lllj to normally maintain a constant temperature in the accumulator.

12. In a steam plant, in combination, a stean. generator, a constant temperature variable Water level accumulator, a passage for steam from said generator to said accumulator, valve mechanism in said passage operating to maintain a constant, pressure in the steam generator, means to supply cold water. to said accumulator, automatic means to control the cold water supply in response to temperature in the accumulator, a hot water consumer and means to conduct hot water from said accumulator to said consumer.

13. The method of operating a steam plant which comprises generating steam at a different rate than the rate of consumption, condensing the surplus steam by means of cold water, regulating the supply of cold water so that the hot water produced by the mixing of steam and cold water is maintained at constant temperature, accumulating hot water thus produced in an accumulator, indicating the height of water in the accumulator and controlling the supply of heat to the generator in accordance with the indicated height of water in the accumulator.

14. In a steam plant, an accumulator having a water space and a steam space, means to supply steam to said accumulator, means to supply cold water to said accumulator to condense said steam and produce hot water, said accumulator being constructed and arranged to store the hot water produced until there is a demand for hot water, means to withdraw hot water-from said accumulator, means to withdraw steam from said accumulator, and means to control the supply of cold water to maintain a constant temperature and pressure in the accumulator except when steam is withdrawn.

15. In a steam plant, an accumulator having a water space and a steam space, means to supply steam to said accumulator, means to supply cold water to said accumulator to condense said steam and produce hot water,

said accumulator being constructed and arranged to store the hot water produced until there is a demand for hot water, means to withdraw hot water from said accumulator, means to withdraw steam from said accumulator and means for controlling the supply of cold water to maintain a constant temperature and pressure in the accumulator when steam is not withdrawn, to shut off the cold water supply when steam is withdrawn and the pressure and temperature drop, and to admit cold water when the pressure and temperature rise again and a given value of temperature is reached.

16. In a steam plant, in combination, a steam generator, an accumulator comprising a receptacle closed to the atmosphere and having a steam space and a water space, a

BEST AVAILABLE cop,

passage for steam from said generator to said accumulator, valve mechanism in said passage operating to maintain a constant pressure in said steam generator, means to supply cold water to said accumulator to condense said steam and produce hot water, said accumulator being constructed and arranged to store the hot water produced until there is a demand for hot water, means to withdraw hot water from said accumulator, means to withdraw steam from said accumulator, and means to control the supply of cold water to maintain a constant temperature and pressure in the accumulator except when steam is withdrawn.

17. In a steam plant, in combination, a steam generator, an accumulator having a steam space and a water space, a passage for steam from said generator to said accumulator, Valve mechanism in said passage operating to maintain a. constant pressure in said steam generator, means to supply cold water to said accumulator to condense said steam and produce hot water, said accumulator being constructed and arranged to store the hot water produced until there is a demand for hot water, means to withdraw hot water from said accumulator, means to withdraw steam from said accumulator, and means to control the supply of cold water to maintain a constant temperature and pressure in the accumulator except when steam is withdrawn, and means for controlling the supply of cold water to maintain a constant temperature and pressure in the accumulator when steam is not withdrawn, to shut off the cold water supply when steam is withdrawn and the pressure and temperature drop, and to admit cold water when the pressure and temperature rise again and a given value of temperature is reached.

18. Accumulator apparatus for steam plants including a steam generator comprising a receptacle closed to the atmosphere and having a steam space and a water space and adapted to operate at pressures ditferent than atmospheric, means to supply surplus generated steam over momentary steam demand to saidreceptacle, means to supply cold water to said receptacle and automatic means normally operating to control the cold water supply to maintain a constant temperature in said receptacle.

J OHANNES RUTHS. 

